Conventionally, an integrated circuit device has been manufactured in which multiple semiconductor chips are mounted on a support substrate, and these semiconductor chips are connected to each other. Normally, the semiconductor chips are connected to each other by wire bonding. However, higher integration of the integrated circuit device is obstructed because some amount of space is necessary to perform the wire bonding. Also, a faster integrated circuit device is obstructed because the resistance of the wires of the wire bonding is high.